The first mile problem in the circular economy supply chains - Collecting recyclable textiles from consumers

Innovative building materials by upcycling clothing waste into thermal energy storage matrix with phase change materials

The current volume of clothing waste reached 115 million tons in 2021 and is projected to increase to approximately 150 million tons by 2030. This significant surge in clothing waste has prompted heightened discussions regarding environmentally friendly recycling methods. Clothing presents complex properties, posing substantial challenges to recycling and usually resulting in environmental pollution when disposed. In this study, our recycling approach capitalizes on the differing melting points of textiles. This transformation was achieved through a physical process that included an opening procedure and high temperature heat compression. Textile materials exhibit exceptional thermal properties. Through experimentation on 50 g fiber specimens, thermal conductivities similar to commercial insulation materials were observed, registering an average of 0.0592 W/m·K at 20 °C and 0.06053 W/m·K at 40 °C. This study explores the impregnation of phase change materials (PCMs) into clothing waste-based specimens, equipping them with heat storage capabilities. During the experimental phase, we employed three distinct types of PCMs to evaluate their thermal properties and heat storage capacities in relation to their respective melting temperatures. Through thermal properties analysis, we determined the latent heat capacity of each specimen, ranging from a minimum of 6.63 J/g to a maximum of 75.81 J/g. Our observations indicated a reduction in peak temperature and time-leg effects attributable to the use of PCMs for surface heat flow. This research underscores the superior thermal performance of construction and building materials derived from clothing waste, enhanced by the integration of PCMs, when compared to traditional materials and other waste-derived alternatives.

The supply and demand balance of recyclable textiles in the Nordic countries

The textile industry is on its early steps towards circular economy. Being a highly resource-intensive and waste-generating industry, it is essential to embrace fiber-to-fiber recycling in addressing the increasing textile waste problem. Several innovative initiatives are happening within this area, not least in the Nordic countries, where automated sorting and fiber-to-fiber recycling technologies and capacities are developing. These large investments require economy of scale; however, this is challenged by the fractioned supply due to the specific fiber requirements of the recycling facilities. To ensure economy of scale and support strategic planning, it is important to investigate the balance of the demand of those capacities with the supply of recyclables generated in the region. Local and regional perspectives are needed in order to avoid unnecessary transportation of low value materials. Based on a synthetises of existing textile flow studies and interviews with relevant actors in four Nordic countries, this study investigates the balance between the supply of recyclable textiles and the sorting and recycling capacity. This is accomplished by estimating the volumes of recyclables and their fiber composition (based on developed weighting average method) and comparing these with the current and upcoming capacities in each country and in the Nordics as a whole. The findings indicate that the upcoming automatic sorting and recycling capacity will be sufficient to deal with the total recyclable fraction in the Nordic region, except for some of the synthetic fibers. However, there are imbalances between supply and demand within individual countries, highlighting opportunities for collaboration.

Open source IoT-based collection bin applied to local plastic recycling

Plastic waste is a major challenge for policy making; it has a terrible impact on the environment if it is not properly managed. In order to mitigate this issue, recycling industries have emerged with the associated logistics chain that also has an environmental impact, notably with the production of greenhouse gas. In addition to using energy to transform plastic waste into source material, energy is also wasted to transport it. In parallel to reducing plastic waste, it may be recycled at a very local scale, reducing transportation and allowing potential improvement of the collecting process. Assuming that local transformation of plastic waste is possible, this article describes the design, assembly, and setup of the hardware, system architecture, and software of collectors that may be used by these recycling units. The specificity of these collectors is that they produces on-line data related to the quantity of waste collected. Once implemented, a network of smart collectors should allow the reduction of travel to collect waste as it notifies when the collectors are full. It also produces data on the scale of a territory to optimize the supply chain related to plastic waste collection. This article presents the design and engineering aspects as well as limitations induced by technical choices, but also potential improvements for future developments.

Reuse of Textile Waste in the Production of Sound Absorption Boards

Textile waste is formed in various stages, from the preparation of raw materials to the utilisation of textile products. One of the sources of textile waste is the production of woollen yarns. During the production of woollen yarns, waste is generated during the mixing, carding, roving, and spinning processes. This waste is disposed of in landfills or cogeneration plants. However, there are many examples of textile waste being recycled and new products being produced. This work deals with acoustic boards made from waste from the production of woollen yarns. This waste was generated in various yarn production processes up to the spinning stage. Due to the parameters, this waste was not suitable for further use in the production of yarns. During the work, the composition of waste from the production of woollen yarns was examined-namely, the amount of fibrous and nonfibrous materials, the composition of impurities, and the parameters of the fibres themselves. It was determined that about 74% of the waste is suitable for the production of acoustic boards. Four series of boards with different densities and different thicknesses were made with waste from the production of woollen yarns. The boards were made in a nonwoven line using carding technology to obtain semi-finished products from the individual layers of combed fibres and thermal treatment of the prepared semi-finished product. The sound absorption coefficients in the sound frequency range between 125 and 2000 Hz were determined for the manufactured boards, and the sound reduction coefficients were calculated. It was found that the acoustic characteristics of soft boards made from woollen yarn waste are very similar to those of classic boards or sound insulation products made from renewable resources. At a board density of 40 kg/m³, the value of the sound absorption coefficient varied from 0.4 to 0.9, and the noise reduction coefficient reached 0.65.